Gate coupling in floating-gate memory cells

Abstract

Methods and apparatus utilizing a stepped floating gate structure to facilitate reduced spacing between adjacent cells without significantly impacting parasitic capacitance. The stepped structure results in a reduced surface area of a first floating gate in close proximity to an adjacent floating gate with substantially no reduction in coupling area, thus facilitating a reduction in parasitic capacitance leading to improved gate coupling characteristics. Also, because of the reduced surface area exposed to adjacent floating gates, the floating gates may be formed with reduced spacing, thus further leading to improved gate coupling characteristics.